The overall objectives of the total project are to characterize the type-specific and interspecific antigens of erythrocytes, serum, and other tissues - especially reproductive tissues - in rhesus monkeys. These immunogenetic markers are then studied for their intrinsic interest as well as for their possible roles in reproduction and development. Our specific goals are: (1) to produce and characterize blood typing reagents; (2) to produce and analyze new alloimmune sera detecting immunoglobulin allotypes; (3) to develop gel electrophoretic technics for detecting enzyme polymorphisms; (4) to study the inheritance and linkage relationships of the blood group markers; (5) to test the hypothesis that newborn rhesus fail to show symptoms of hemolytic disease because the antibodies passively acquired from the mother are too weak; (6) to initiate feasibility studies on the production of antisera to sperm specific isozymes (e.g. LDH) and to study the use of these antisera to suppress fertility.